> For the complete documentation index, see [llms.txt](https://fabco.gitbook.io/dappy-spec/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://fabco.gitbook.io/dappy-spec/sections-specific-to-browser-and-web-applications/content-security-policy-csp.md).

# Content Security Policy (CSP)

CSP is a great feature of modern browser, it is 100% supported by dappy. A major difference though is that the web servers have no control over it, the CSP is not defined by the HTTP headers on the first top level navigation request, neither are they defined by html meta tags.

**CSP rules are defined at the name system level, making it rock solid and impossible to change by any MITM attack or server intrusion.**

See [Mozilla's documentation on CSP](https://developer.mozilla.org/en/docs/Web/HTTP/CSP)

[Our implementation](https://github.com/fabcotech/dappy/blob/master/main/overrideHttpProtocols.ts#L275)

An example of a value `csp` in the configuration for a record `mysite`:

```
{
  "values": [
    ...,
    {
      "kind": "csp",
      "value": ""default-src 'self' mysite; script-src https://mysite; img-src https://mysite https://mysecondsite"
    }
  ]
}
```